0 votes 0 votes Two hosts $L1$ and $L2$ are connected via a communication link. The host $L2$ has a buffer for receiving data of total size $6000$ $Bytes$. The $2000$ $Bytes$ of received data (unprocessed data) is present in the receiver buffer at host $L2$. If the size of congestion window at host $L1$ is $3500$ $Bytes$, the maximum sending window size at host $L1$ is ________. GATE tbb-mockgate-3 numerical-answers computer-networks sliding-window + – Bikram asked Feb 9, 2017 retagged Sep 15, 2020 by ajaysoni1924 Bikram 455 views answer comment Share Follow See all 3 Comments See all 3 3 Comments reply Lucky sunda commented Feb 10, 2017 reply Follow Share One doubt..Why it is not 4000 bytes. Are there two buffers for reciving and sending purpose at a host?Is congestion window same as receiving window? 0 votes 0 votes Bikram commented Mar 20, 2017 reply Follow Share @lucky , please read my below answer. There are two buffers for receiving and sending purpose at a host , and congestion window is NOT same as receiving window . 0 votes 0 votes JashanArora commented Jan 16, 2020 reply Follow Share Size of receiver's buffer = 6000 B Available size in receiver = 4000 B (Advertised Window / rwnd) cwnd = 3500 B (given) Sender Window Size = min(cwnd, rwnd) = 3500 B. https://inst.eecs.berkeley.edu/~cs168/fa14/lectures/lec14-public.pdf 1 votes 1 votes Please log in or register to add a comment.
Best answer 3 votes 3 votes Available Window size in L2 =6000 - 2000 = 4000 Bytes . So in L1, window size=min (rwnd, cwnd) =min(4000,3500)B =3500 B Bikram answered Mar 20, 2017 selected Sep 8, 2019 by Bikram Bikram comment Share Follow See all 2 Comments See all 2 2 Comments reply Satyajeet Singh commented Jan 16, 2018 reply Follow Share @Bikram Sir, I agree that the current (available) window size at sender is 3500B but in the question it is asking for the maximum possible size of the sender window. We know the reciever has 2000B of outstanding data unprocessed data in its buffer. Does it mean that sender has this 2000B of data unacknowleged and hence these bytes are outstanding bytes as per the sliding window protocol. If sliding window case is taken, it may mean that sender window size has 2000B outstanding data(yet to be acknowledges )+ 3500B of data that can be sent= 5500B window size. 0 votes 0 votes amitqy commented Jan 31, 2019 reply Follow Share so sender's current window size in TCP is also said as congestion window, right ? 0 votes 0 votes Please log in or register to add a comment.